In the general industrial machinery fields, a mechanical-system control element is driven by an electric motor. However, in recent years, there have been proposed and developed various mechanically and electrically integrated electric drive apparatus, in which an electronic control unit that is configured to control a rotational speed and a rotational torque of an electric motor and comprised of a semiconductor device or the like, is integrally incorporated in the electric motor.
For instance in an automotive electric power steering apparatus exemplified as a mechanically and electrically integrated electric drive apparatus, both of a rotational direction and a rotational torque of a steering shaft, which is rotated by operating a steering wheel by the driver, are detected. The automotive electric power steering apparatus is configured to drive the electric motor so as to rotate the steering shaft in the same direction as the rotational direction of the steering shaft on the basis of the detected values, thereby generating a steering assist torque. In order to control the electric motor, an electronic control unit (ECU: Electronic Control Unit) is provided or incorporated in the power steering apparatus.
As a prior-art electric power steering apparatus, Japanese patent provisional publication No. JP2013-60119 A (Patent document 1) discloses such an electric power steering apparatus. Disclosed in the Patent document 1 is an electric power steering apparatus, which is constructed by an electric motor and an electronic control unit. The electric motor is housed in a motor housing having a cylindrical portion made of aluminum alloy or the like, whereas the electronic control unit is housed in an ECU housing, which is located on the opposite side to an output shaft in an axial direction of the motor housing. The electronic control unit, which is housed in the ECU housing, is equipped with a power-supply circuit unit, a power-conversion circuit unit having a power switching element, such as a MOSFET, an IGBT or the like, for driving and controlling the electric motor, and a control circuit unit for controlling the power switching element. An output terminal of the power switching element and an input terminal of the electric motor are electrically connected to each other through a bus bar.
Electric power is supplied from a power source through a connector terminal assembly made of synthetic resin to the electronic control unit, which is housed in the ECU housing. Also, detection signals from detection sensors, representing operating conditions and the like, are supplied to the electronic control unit. The connector terminal assembly also functions as a lid body. Hence, the connector terminal assembly is connected to the electronic control unit in a manner so as to close an opening formed in the ECU housing. Also, the connector terminal assembly is fixedly connected to an outside surface of the ECU housing with fixing bolts.
As other electric drive apparatus, in which an electronic control unit is integrally incorporated, an electric brake, electric hydraulic controllers (regulators) for various hydraulic controls and the like are well known.